import java.util.Scanner;

public class 圆的面积和周长 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入圆的半径：");
        double r = scanner.nextDouble();
        double area = Math.PI * r * r;
        double circumference = 2 * r * Math.PI;
        System.out.println("圆的周长为：" + circumference);
        System.out.println("圆的面积为：" + area);
    }

    public static void circle(double r, double area, double circumference) {
        System.out.println();
    }
}
